The present invention relates to apparatus used to swage ferrules onto the outer wall of cylindrical member such as a tube end. More particularly, the invention relates to a swaging apparatus in which a hydraulic drive section is isolated and separable from a size adapter tool that includes a driven member that swages the ferrule by applying an axial force thereto against a coupling nut. This application claims the benefit of U.S.
Ferrule type tube fittings are well known and characteristically include a threaded coupling nut, a threaded coupling body and one or more ferrules that fit inside the coupling nut. The coupling body typically includes a camming surface that engages a camming surface on a ferrule. A cylindrical member such as, for example, a tube end, is slid into the coupling body with the ferrules closely surrounding the outer wall of the tube end. When the coupling nut is installed onto the threaded end of the coupling body, an axial force is applied to the ferrule or ferrules which produces a swaging action thereby causing a radial displacement of portions of each ferrule body, causing the ferrules to tightly grip the outer wall of the tube end.
In many applications the fitting can be assembled with the use of simple hand tools such as wrenches. However, with larger tube sizes and with tubing made of harder materials, it is often necessary to use fluid pressure to apply sufficient force to properly swage the ferrules onto the tubing. Furthermore in some applications it is desirable to have the ability to assemble many fittings in an expedient manner.
Many types of power assisted swaging apparatus have been developed over the years. One type of such a tool is a hydraulic swaging apparatus in which a piston is driven axially by hydraulic pressure. The piston in turn displaces a driven member or anvil that applies the axial force to the ferrules. Such apparatus are described in U.S. Pat. Nos. 3,722,064; 3,810,296; 3,728,771; 4,873,755 and 5,027,489 the entire disclosures of which are fully incorporated herein by reference.
A characteristic of known swaging apparatus is that often times the driven member used to apply the axial force to the ferrules is integral with the hydraulic piston. If the same size ferrule or tubing is always going to be used, this is not an inconvenience, but as is more frequently the case, the apparatus must be able to swage ferrules of various sizes. Thus, a size change could require a disassembly of the hydraulic section as well. Alternatively, it is known to make the driven member separate from the piston, but even in such designs the driven member may be used to retain the piston in the apparatus housing, so that if size changes need to be made, the hydraulic section is probably going to be disassembled or at a minimum prone to leakage.
It is therefore an objective of the present invention to provide apparatus for swaging ferrules onto cylindrical members using fluid pressure, with the apparatus having substantial flexibility in making size changes without compromising or needing to disassemble the hydraulic drive section of the apparatus. It is a further objective to provide a more compact and user friendly swaging tool that is easier to use and provides a visual indication that a swaging operation has been successfully completed.
To the accomplishment of the aforementioned and other objectives, and in accordance with one embodiment of the invention, an apparatus for swaging a ferrule or ferrules onto an outer wall of a cylindrical member includes a hydraulic power section and an adapter tool. The hydraulic section is disposed within a housing, and the adapter tool is at least partly retained in the housing and also is fully removable from the housing without affecting the hydraulic power section of the apparatus. The hydraulic section includes a piston that is moved under force of hydraulic pressure applied thereto from a hydraulic pressure source connectable to the apparatus. The adapter tool includes a driven swaging member or anvil that is moved from a first or retracted position to a second or extended position in response to movement of the piston. The adapter tool also includes a threaded sleeve onto which a coupling nut can be installed. Preferably, but not necessarily, the sleeve and anvil are releasably secured together so that the adapter tool can be removed from the housing as a unitary assembly. Size changes can be accommodated by removing a first adapter tool of a given size and replacing it with a second adapter tool of a different size. This changeover can be implemented without any disassembly or compromise of the hydraulic section.
In accordance with another aspect of the invention, the apparatus includes a visual indicator that a swaging operation has been successfully completed. In the preferred embodiment, this visual indication is realized in the form of an indicator knob that pops out axially from the back end of the apparatus when a swaging operation is completed. The knob is reset manually before the start of the next swaging operation.
These and other aspects and advantages of the present invention will be apparent to anyone skilled in the art from the following description of the preferred embodiments in view of the accompanying drawings.